1. Field of the Invention
The present invention relates to a spring connector, more specifically, to a method of fabricating a spring connector.
2. The Related Art
According to progress of electrical technology, various consumer products are developed and popular, such as digital cameras, digital video recorders, mobile phones, etc. The consumer products are equipped with a battery to achieve long-term use. The battery will provide energy to the consumer products through a spring connector interconnecting the battery and a printed circuit board of the consumer products.
A conventional spring connector includes an insulating housing, a conductive spring and a metal plunger. The conductive spring and the metal plunger are received in the insulating housing. One end portion of the conductive spring connects a bottom portion of the metal plunger, and the other end portion connects the printed circuit board of the consumer products. A top portion of the metal plunger connects the battery. Hence the energy will be transmitted to the printed circuit board through the metal plunger and the conduct spring.
However, the conducting path of the conductive spring is long and the resistance of the conductive spring is variable because the conductive spring will be compressed by the metal plunger. Hence, the conducting quality of the spring connector will be reduced.
Please refer to FIG. 1 and FIG. 2. Another conventional spring connector 900 includes a metal barrel 902, a metal plunger 904 and a coil spring 906. The metal barrel 902 includes a bottom plate 908 horizontally extended from a bottom portion thereof, a first shoulder 910 bent inward from a top portion thereof, an opening 912 defined at a middle portion of the first shoulder 910, a first receiving space 914 defined therein and a first concavity 916 defined at a top surface of the bottom plate 908 and positioned in the first receiving space 914.
The metal plunger 904 includes a narrow head portion 918, a wide sliding portion 920 extended from a bottom portion of the narrow head portion 918, a second shoulder 922 formed between the narrow head portion 918 and the wide sliding portion 920, a second receiving space 924 defined therein and opened at a bottom surface of the wide sliding portion 920 and a second concavity 926 defined at a top portion of the second receiving space 924.
Please refer to FIG. 3 to FIG. 6. A fabricating method of the conventional spring connector 900 includes following steps:    step 802: lathing the metal barrel 902 and the metal plunger 904, and providing the coil spring 906;    step 804: positioning the coil spring 906 in the first receiving space 914 of the metal barrel 902, and connecting a bottom portion of the coil spring 906 to the first concavity 916 of the bottom plate 908;    step 806: positioning the wide sliding portion 920 of the metal plunger 904 in the first receiving space 914 to connect the first receiving space 914 of the metal barrel 902 to the second receiving space 924, enclosing a top portion of the coil spring 906 in the second receiving space 924 of the metal plunger 904, and connecting a top portion of the coil spring 906 to the second concavity 926; and    step 808: bending the top portion of the metal barrel 902 inwardly to form the first shoulder 910 and the opening 912 by an assisting tool, engaging the first shoulder 910 of the metal barrel 902 with the second shoulder 922 of the metal plunger 904 to retain to wide sliding portion 920 of the metal plunger 904 in the first receiving space 914 of the metal barrel 902 and expose the metal plunger 904 outside the opening 912 of the metal barrel 902.
The bottom plate 908 of the metal barrel 902 connects to the printed circuit board of the consumer products. The narrow head potion 918 of the metal plunger 904 connects to the battery and is pressed to slide into the first receiving space 914 of the metal barrel 902 by the battery. Hence, the metal plunger 904 is biased to connect to the metal barrel 902 because the opposite ends of the coil spring 906 abut against the first concavity 916 of the metal barrel 902 and the second concavity 926 of the metal plunger 904.
The energy will be transmitted from the battery to the printed circuit board through the metal plunger 904 and the metal barrel 902. The conducting path is therefore reduced to improve the conducting quality.
However, the conventional spring connector 900 includes the following defects. First, the first concavity 916 of the metal barrel 902 is hardly to be coated a high conductive material. Second, the resistance of the spring connector 900 will be increased if the coating layer on the first concavity 916 is uneven. Third, the temperature of the spring connector 900 will be improved in used if the coating layer on the first concavity 916 is uneven. Fourth, the metal barrel 902 is hard to be fabricated by lathing and the cost thereof will be increased.